The effects of protamine sulfate on clot formation time and clot strength thromboelastography variables for canine blood samples

Abstract

Results indicated protamine prolonged clot formation time and decreased overall clot strength in a dose-dependent manner; such effects may contribute to a hypocoagulable state in dogs. Kaolin-activated and nonactivated blood samples were appropriate for measurement of the effects of protamine on coagulation. Administration of protamine to reverse the effects of heparin should be performed with caution.

Is There a “Blind Spot” in Point-of-Care Testing for Residual Heparin After Cardiopulmonary Bypass? A Prospective, Observational Cohort Study

“…7 The most likely explanation for this phenomenon is a possible liberation of protamine due to degradation of heparin by heparinase resulting in an elongation of the CT by protamine. 11 , 12 , 19 Additionally, results of the present study suggest that excess protamine due to P: H ratios >1.0 could have a negative influence on INTEM: HEPTEM CT ratio measurements as well. This is in line with measurements in blood samples from healthy volunteers, that showed an influence of increasing P: H ratios on the HEPTEM CT. 7…”

“…7 The most likely explanation for this phenomenon is a possible liberation of protamine due to degradation of heparin by heparinase resulting in an elongation of the CT by protamine. 11,12,19 Additionally, results of the present study suggest that excess protamine due to P: H ratios >1.0 could have a negative influence on INTEM: HEPTEM CT ratio measurements as well. This is in line with measurements in blood samples from healthy volunteers, that showed an influence of increasing P: H ratios on the HEPTEM CT. 7 As a clinical implication from the results of the present study, we believe it is necessary to complement existing POC algorithms with regard to the interpretation of INTEM: HEP-TEM CT ratio, taking the timepoint of protamine administration and the P: H ratio into consideration.…”

“…The negative effects of excess protamine on the coagulation system have been demonstrated repeatedly. [9][10][11][12][13] Therefore, it is important to ensure for a high specificity in a method used for the diagnosis of residual heparinization to minimize the number of false positive tests, since these patients are at risk to receive protamine unnecessarily with all the negative consequences mentioned above.…”

Caltrop-like Small-Molecule Antidotes That Neutralize Unfractionated Heparin and Low-Molecular-Weight Heparin In Vivo

“…At the high dosage of 20 μg/mL, the clot strength became significantly decreased, which was a common phenomenon for heparin antidotes, including protamine. 21,52 Control aPTT assays with bovine plasma revealed that adding TP-1−3 of less than 54, 45, or 23 μg/mL, respectively, did not cause abnormality of the aPTT values, which were still in the normal range (23−37s) (Figures 6e and S20a,b). These results support that, at least within a quite wide dose window, TP-1− 3 did not interact significantly with the components of the plasma related to coagulation or the reagents used to prevent coagulation to prepare plasma.…”